When extracting COM data, the registry data section has a key created as
[$componentName] or [$fileName] (I can't tell which since the key file name is the component name.)
I think this means to use the path that component/file will be installed to. Is this correct?

I've also seen
[!componentName] or [!fileName]
I think this means the full path and file name of that file. Is this correct?

In a third place in I see
[\"][\[]{BIN_WIN} [INSTALLDIR]bin[\]]myFile.dll[\"]

I think this is because double-quotes, open square bracket, and close square bracket need to be escaped. ({BIN_WIN} in the target path for my code, the bin subdirectory of [INSTALLDIR].

Are these documented anywhere?
Can these be used anywhere else?
Can I merge them with other text? For example by setting the registry to [!fileName]\otherfilename.ext